1. Field of the Invention
This invention relates to automatically controlled vehicles. In one of its aspects, the invention relates to an automatically controlled vehicle which has the ability to process coded information and to guide the vehicle responsive hereto.
2. State of the Prior Art
In commonly assigned U.S. Pat. No. 3,935,922 issued Feb. 3, 1976, there is disclosed and claimed a vehicle guidance system for guiding a vehicle along a predetermined invisible guide line containing fluorescent material. The guidance system includes a sensing head having three photocells to detect the position of the guide line with respect to the vehicle. The photocells are focused on an area of the floor directly beneath the sensing head and gathered light from that area as a whole is used to guide the vehicle along the guide line. The "area" sensing technique makes it difficult to control the vehicle along branch lines without extensive electrical and/or optical alterations. Further, this prior technique makes it difficult for the vehicle to distinguish between one of two or more adjacent guide lines within the sensor's field of view. Still further, the ability to read, store and execute a large number of coded instructions is difficult with conventional electronics.
Automatically guided vehicles which can be programmed to follow a predetermined course reponsive to coded instructions in the floor are known. For example, the DeLiban U.S. Pat. No. 3,147,817 (issued Sept. 8, 1964) and Paulus et al U.S. Pat. No. 2,317,400 (issued Apr. 27, 1943) and Kohls 3,411,603 (issued Nov. 19, 1968). Each of these systems, however, uses buried wires and does not use reflected or simulated emission light.
Automatically guided vehicles which use reflected light and photocells to detect the position of a reflected light guide line are disclosed in the U.S. patents to Vischulius Nos. 3,718,821 (issued Feb. 27, 1973); Kubo 3,738,433 (issued June 12, 1973); Ando et al 3,881,561 (issued May 6, 1975); and Wesener 3,628,624 (issued Dec. 21, 1971).